Odoo: How to inherit <templates> of web module?

templates_inherit_demo

REF LINK: https://www.odoo.com/forum/help-1/question/odoo10-how-to-inherit-templates-of-web-module-119140#answer-119142

This is main template:

<template id="template" xml:space="preserve">
    <t t-name="DemoExample">
        <div class="demo-one">
            <p>odoo</p>
        </div>
    </t>
</template>


How To Inherit
----------------------
Template file :-> demo_template.xml

<template id="template" xml:space="preserve">
    <t t-name="DemoExample" t-extend="DemoExample">
        <t t-jquery='.demo-one' t-operation='replace'>
            <p>Your Company Name</p>
        </t>
    </t>
</template>

-----------------------------------------------------
<!- Loaded XML files inside java script code -->
-----------------------------------------------------
JS file :-->  demo_example.js

-------------------------------------------------------------------------
put the following JS Code in demo_example.js file:
-------------------------------------------------------------------------

odoo.define('module_name.name_of_fetures', function (require) {
'use strict';
var core = require('web.core');
var ajax = require('web.ajax');
var qweb = core.qweb;
ajax.loadXML('/module_name/static/src/xml/demo_template.xml', qweb);
});

-----------------------------------
Loading of Javascript file 
-----------------------------------
<template id="demo_example_ext_js" name="Demo Example Ext Js" inherit_id="web.assets_backend">
    <xpath expr="." position="inside">
        <script type="text/javascript" src="/module_name/static/js/demo_example.js"></script>
    </xpath>
</template>

hi all i want to change tooltip question marker to "!" how to inherit templates to change this on
there is source code in: addons/web/static/src/views/form/form_lable.xml

and source code is:

<t t-name="web.FormLabel">
    <label class="o_form_label" t-att-for="props.id" t-att-class="className" >
        <t t-esc="props.string"/><sup class="text-info p-1" t-if="hasTooltip" t-att="{'data-tooltip-template': 'web.FieldTooltip', 'data-tooltip-info': tooltipInfo, 'data-tooltip-touch-tap-to-show': 'true'}">?</sup>
    </label>
</t>

please help me tnx